Evaporator for refrigerating apparatus



Oct. 23, 1928.

L. BRUEHL EVAPORATOR FOR REFRIGEBATWG APPARATUS Filed Jan. 4, 1927 new oct. '23. 1928.

UNITED STATES.

11.688377, PATENT oFF cE'.

. mwfa'nnonnnun'nn, ori'BnooxLYN, NEW Yonx, Assremoa r Gasman-monumencozaronarron, or scnmron, PENNSYLVANIA)? A. conronnrron DIE-DELAWARE;

nvnroaa'ron FORBEFRIGERATING arraaa'rus.

Application filed was 4-, 192?, ser al 110,1583.

0 sorbent liquid is also evaporated and passes.

- over to the condenser 'and thence to the evaporator. As this liquid is not volatile to any considerable extent at the low tem= perature existing in the evaporatorduring' the absorbing period, it will remain in the evaporator. After alargenumbe'r of alternate heating and absorbing periods, there may accumulate'such a quantity of the'abysorbent liquid in the evaporator as will seriously interfere with the efliciency of the apparatus.

The main object' of the present invention is to effect the automatic return of liquid from the evaporator to the absorber during each cycle of operation'and to thereby main tain at all times properoperating conditions.

The present invention is an improvement in the apparatus disclosed and broadly claimed in the Otto and J'ankus Patent 1,582,882 issued April 27, 1926.

v As one important feature of my invention I provide a single chamber which serves both as a receiver for the liquid drained from the body of the eva orator, and as a pressure chamber in whic gas expands toforce the liquid to a higher level. p

As another important feature of the invention, the pressure chamber is mounted in-' side of the evaporator so that" itis not subjected to as wide or rapid fiuctuations'of temperature. s

As a further important feature of the present invention, I provide a simplified means for conducting liquid from the bottom of the evaporator to the return or suction pipe. 1, c In the accompanying drawings, I have illustrated diagrammatically certain embodiments of my invention.

' In these drawings: Figs. 1 and 2 are vertical sections through evaporators embodying my invention; and

Figs. 3 and 4 are details of alternative constructions of apart thereof.

Inthe construction shown in Fig.1, there om the absorb tor, and serves for the delivery of the .hquefied refrigerant tothe evaporator duris providedan evaporator 10, which maybe of any suit'able'size, form or construction dependent upon the character of, the apparatus in rconnection'with'whichit is, to be used and which is to be cooled thereby. I

have shown this evaporator as a simple cylindrical drum, butsuch form is not in any way' essential. A conduit 11 communicates with the upper part of the evapora-'- ing the heating period, and for the return of gas from the evaporator during the absorbmg or cooling period.

connection, with .the evaporator,

'whether of the form shown. in Fig. 1, or of other form I provide ach'amber 12 which is closed at the top and sides, but communicates at the bottom with a tube 13. The chamber tion of the evaporator by means of a port 14 which is of verysmall size so as to. per-' mit a restricted flow therethrough.

' A conduit 15 connects the lower portion of the tube 13 with the conduit 11. The connection is such that during the delivery of liquid to theevaporator through the conduit 11, the liquid will flow directly into the [evaporator and'will not use down the con-' duit 1'5. This is accomp ished in the form shown in F i 1 by providing the conduit 15. with a hen or goose-neck 16 which enters the upper side of the conduit-11.

Preferably, the discharge end of the pipe 15 delivers in the direction of the return flow of'gas in the conduit 11 so that this liquid is carried along the conduit both by suction and its own velocit j It will be noted that the lower portion of the evaporator communicates with the chamber 12 throu h the port 14 and the tube 13. i

It will also e noted that the chamber ,12

communicates with the return conduit '11 throu h the conduit 13 and the conduit 15, but t at this passage has a larger crosssectional area than the port 14. The port .14 is so positioned that'hquid from the bot-' tom of the evaporator may drain through the port 14; into the tube-13. This drainage may be facilitated by providing a sump 17 at the bottom of the evaporator and around a portion of the tube 13' and placing the port 14 at the lower part of this sump.

The operation is substantially as follows:

At the beginning of the heating period, the pressure increases in thesystem and approximately the same pressure will exist in the chamber 12 as in the body of the evaporator. As the pressure increases any residual liquid in the bottom of the evaporator will be slowly forced through the port 13 and will rise into the chamber 12. The gas in the compartment 12 is compressed and is liquefied by reason of the increasein pressure. This compartment may become entirelyfilled with liquid, there being no gas space remaining.

. in ,the evaporator at the beginnin evaporating or cooling period an At the end of the heating period and the beginning of the cooling period, the pressure in the-evaporator will rapidly decrease. Some of the liquid in the chamber 12 will gasify and the remainin liquid in the compartment 12 will be orced out of this chamber b this gasification. It can do this through tlie port 14 to the lowerpart of the evaporator and it can also do this through the tube 13. and 15 to the return conduit 11. As the first mentioned communication is a restricted one, while the other is open, the major portion of the liquid in the liquid in the compartment 12 will be delivered through the conduit 13 and up the conduit 15 to the return pipe 11. As there is' a suction in this pipe, any liquid entering it will not flow down and. out through the open end of the conduit 11, but ,will be carried along by the gas and will be conveyed back to the absorber. I This liquid which is thus returned is that which remained 'unevaporated at the end of the cooling period and which contains any liquid absorbent which may have collected in the evaporator. Thus during each cycle of operation a predetermined amount of liquid from the bottom of the evaporator and containing liquid absorbent, if there be any or not, will be removed from the evaporator. If any foul gas be present in the system it. will not collect in the chamber 12 as the, alternate filling and emptyin of the chamber will act to move such {on gas therefrom.

It is desirable that the parts be so proportionedthat the distance from' the port 14 to the bottom of the conduit 15 is greater than is the distance from said port 134 to the liquid level in the chamber 12. Thus the weight of the column of liquid in the conduit 13 will cause liquid to rise in the conduit 15 to the point above the liquid level of the the re- 7 turn flow through the conduit 15 will be facilitated. r

In Fig. 1 the levels are shown as they are at the beginning oh the heating period. After the liquid has been returned from the compartment 12 fluctuations in the operation may cause liquid to intermittently enter the conduit 1% through the port 1 1. and then be forced up the pipe 15. This operation is not desired and therefore I preferably provide an enlargement 18 in the conduit 15 toward the upper part which will permit separation of liquid and gas rising in the conduit 15 and the return flow of liquid from said enlargement instead of the delivery of such liquid to the conduit 11. The entire conduit 15 is protected against direct 'influence of outside heat conditions so as to minimize the vaporization in this conduit.

The walls of the compartment 12 are preferabl made comparatively thick and of meta so that they have a certain cold storage capacity and this compartment will not be subject to as great temperature fluctuations as is the case with the outer walls of the evaporator. If the evaporator be employed in an air chamber, the enlargement 18 is not necessary because air has a very loyv conductivity and heat storage capacity; but it is desirable if the evaporator is sui rounded brine. It is not essential that the sump be provided, but it is desirable to employ it, as it facilitates the drainage of liquid from the evaporator to the port 14.

In Fig. 2 there is shown a very similar construction in which the tubes 15 and 13 are formed as parts of a single conduit and as two upstanding arms of a U connection. In other words, in Fig. 2 I have shown the two. conduits which connect the chamber 12 to the gas outlet pipe as arranged side by side, whereas in Fig. 1, one is mounted in side of the other. Otherwise the two con.- structions are substantially the same.

Instead of connecting the conduit. 15 to the gas conduit 11 b a goose-neck as shown in Figs. 1 and 2, t e conduits may be ar-' ranged one inside of the other. In Fig. 3,

I'have shown a conduit 15 of smaller size than the gas conduit '11 and projecting into the open end of the latter. Liquid flowing down the conduit 11 will go direct to the reservoir while liquid flowing up the conduit 15 will be caught in the flow of return gas and carried back to the absorber with said throughthe conduit, 11 overflows into the.

evaporator through the port 19, while liq-'- uid delivered up the pipe 15 will pass from' the nozzle 20 into the port 19 and thus back to the absorber.

Iclaimis; a I I l An evaporator: for an. absorption -re-- 'frigerating system including a mameva -c ompartment enclosed wit whereb the compartment is v rotected from rowing unis described my invention, what rator vessel, 1; gas outlet -conduit, .an a

direct eat 1 interchange wit the medium surrounding said vessel, said compartmenthaving restricted communication with-the 3 lower part of said vesseland-open commu'ni I compartment is protected from direct heat .sorption cation with said conduit.

. 2. An eva rator vessel "for intermittently operated re i'gerating apparatus of the. ab-

closed wit the evaporator whereby the interch c with the medium surrounding saidvesse said; eompartment beingin re stricted' communicationwith the lower part thereof, and a conduit leadi 'from' said conduit leading fromthe' lower part thereof and provided with a restricted port com and acon uit connected to said first.men-' municatin withthe'lower partof the vessel,

tioned conduit. for the delivery of liquid vfrom the compartment to the exterior of the evaporator.

An evaporator :for' refrigerating appa ratus includieg a vessel, a conduit c'ommumeating with e'upper portionthereof for the delivery of-gas 1; 4

' the 'lowerjpart of: the vessel'to sai conduit t a point, spaced from the end of thelatter; 5 y 5. evaporator for refrigerating appa vessel'for delivering .li u id'from ratusincludmg' a vowel, a conduit having lmeansfor delivery ofliquid thereto and the g'es therefrom, a eompartu said vessel having 2 compartment en 1 sa1d 'second mentione end within said vessel and so 10 a ative to the first mentioned conduit that the liquid returned from the secondof liquid to the vessel and the from the vessel and means ment having in the 'lower portion thereof restricted communication with the 'lower rtion of the vessel, and aconduit anneaingsaid com artmentwith said first m'en-I tioned.condu1twithin' the 11 per' part 0 said vessel for dumpin% liqui directlyint'o the latter whereby e ow-of gas from the evaporator-"will carry such'liquidtherewith.

: -6. An evaporator for refrigerating apparatus including a,vessel, aconduit for delivering liquid-thereto and withdrawing gas therefrom, a second conduit for deliverm liquid from-the lower portion of the vesse directly to said first mentioned conduit and having an enlargement therein intermediate .to the ends thereof. Q 7 An evaporator for refrigerating appa-- ratus including-a vessel, a'c'onduit for de livering liquid thereto. and withdra ing gas therefrom, a second conduit for delivering,

li aid from the lowerportion. of the vessel directly to said first mentioned] conduit :within the upper (part of said vessel, and a compartment within said vessel and having part closedaudits lower part its upper inopen communication with the second mentioned conduit and in restricted communicationwith the lower fpart of said vessel.

- 8.' An evaporator or refrigerating ap 'aratus including-a vessel, a conduit for elivering liquid thereto and withdrawing gas therefrom, a second conduit for delivermg liquid from the lower ortion of the ,vesse conduit having its discharge cated re mentioned conduitis delivered directly to said first mentioned conduit in: the direction of the efiiuent ofthe latter and away from.

the evaporator.

Signed Kings at Brooklyn, in the county of *and State of New York, this "31st day of December A. D. 1926.

- LAWRENCE BRUEHIR 

